Glad your new pet ate. Just make sure it's warm water that you heat it up in and not hot so it doesn't start to cook the rat, especially if they're smaller sizes. It might also help to dry the rat off some with paper towels for a few seconds so it's not so wet when offered. I thaw mine in water too and have some that won't eat if it's too wet. You could also just take from your cooler water, quick towel dry then warm up with a hair dryer.